In clinical practice, rapid diagnosis of acute neurological diseases from electroencephalographic (EEG) observations is highly important. But the current method of affixing EEG electrodes to the scalp is tedious, taking several minutes for each electrode. In addition, to acquire a single channel of EEG, at least three electrodes must be wired (e.g., using electrode leads) to an amplifier. Wires tangling can cause signal distortion and it make it inconvenient to acquire EEG in emergency, mobile, and certain applications, such as in critical, ambulatory care or sleep studies. Although there are portable EEG devices available, these devices still require installation of multiple distinct electrodes on the scalp and wire connections to individual electrodes which consume precious time in critical care, and often cause wire tangling, signal interruption, and friction noise.